Technics RS-M226 Manuale utente

ORDER

NO.

ARD82060161C8-11

Service

Manual

Cassette

Deck

Soft-Touch

Cassette

RS-M226

Deck

with

Dolby

B-C

NR

(ee

Sied

Silver

Face

This

is

the

Service

Manual

for

the

}

|

following

areas.

a)

oe

For

all

European

areas

|

except

United

Kingdom.

|B)

eee

For

United

Kingdom.

|

DC

[porev

8-c

nm

Please

use

this

service

manual

for

the

RS-M226.

(Discard

the

service

manual

prepared

for

the

order

No.

ARD82050142C8-11.)

RS-M24

MECHANISM

SERIES

Specifications

Track

system:

4-track

2-channel

stereo

recording

and

playback

Inputs:

MIC;

sensitivity

0.25

mV,

applicable

microphone

r.

a

ety

impedance

4002—10kQ—

gee

SReees

Ones

LINE;

sensitivity

60

mV,

input

impedance

more

Wow

and

flutter:

0.048%

(WRMS),

+0.14%

(DIN)

er

.

ce

ae

eee

:

ut

lev

m

impedan

Frequency

response:

Metal

tape;

20—18,000Hz

ae

less

ia

23

ko

Dia

ee

aos

30—

17,000

Hz

(DIN)

HEADPHONES;

output

level

80mV

(82)

CrOz

tape;

20—18,000Hz

applicable

headphone

impedance

8

2—600

Q

30—

16,000

Hz

(DIN)

Bias

frequency

:

80

kHz

Normal

tape;

20

17,000Hz

Motor:

Electrical

DC

governor

motor

30

—

15,000Hz

(DIN)

Heads:

2-head

system

1

MX

head

for

rec/playback

Signal-to-noise

ratio:

Dolby

C

NR

in;

75dB

(CCIR)

1

double-gap

ferrite

head

for

erasure

Dolby

B

NR

in;

67 dB

(CCIR)

Power

requirements:

[DB]

---

AC

220

V,

50-60

Hz

NR

out:

57dB

(for

all

European

areas

except

United

Kingdom.)

(signal

level=max.

input

level

A

weighted,

CrO

eee

gnal

level

=max.

input

level

A

weighted,

CrO2

;

(only

for

United

Kingdom.)

type

tape)

Power

consumption:

12W

Fast

forward

and

Dimensions:

43.0

cm(W)

x

10.9cm(H)

X

23.3

cm(D)

rewind

time:

Approx.

90

seconds

with

C-60

cassette

tape

Weight:

4

Okg

Specifications

are

subject

to

change

without

notice.

*

‘Dolby’

and

the

double-D

symbol

are

trademarks

of

Dolby

Laboratories.

Technics

Matsushita

Electric

Trading

Co.,

Ltd.

P.O.

Box

288,

Central

Osaka

Japan

RS-M226

CONTENTS

ITEM

PAGE

ITEM

PAGE

LOCATION

OF

CONTROLS

BLOCK

DIAGRAM

cercccrcereecerceeetecereeeeeeneaeeetenans

9

AND

COMPONENTS

-oeeccccceeeeteeteeteseeeeseeeeeees

2

SCHEMATIC

DIAGRAM

-rcccceeeereeccectcececeeeeeeeess

13

DISASSEMBLY

INSTRUCTIONS

3

-+-trr-srsrse

sere

2

CIRCUIT

BOARDS

AND

MEASURMENT

AND

WIRING

CONNECTION

DIAGRAM

-+++++ee-++0+

15

ADJUSTMENT

METHODS

---eeccceerreeeteteet

teres

3

MECHANICAL

PARTS

LOCATION

-orrrereeeceertee:

18

ELECTRICAL

PARTS

LOCATION

crveersrcteeeteete

8

CABINET

PARTS

LOCATION

-orerreecccterrreeteenteees

22

LOCATION

OF

CONTROLS

AND

COMPONENTS

7

Headphones

Jack

(phones)

Tape

Counter

(tape

counter)

Power

Switch

[power

(push

on)]

Recording

Indicator

(rec)

Eject

Button

(eject)

Input

Select

Button

{input

select

(Mlinee

=

mic)|

Cassette

Holder

FL

(fluorescent

level)

Meter

|

XX

___|

@

Input

Level

Controis

[input

level(L

->

R)]

Gar

Selector

{tape

select

(NormaleCrOzeMetal)|

Fast

Forward/Cue

Button

(ff/cue

(PP

)])

Dolby

Noise

Reduction

Select

Counter

Reset

Button

Switch

[Dolby

NR

(2

Be

=

@)]

{counter

reset)

Rewind/

Review

Button

[rew/rev

(

44

)]

Microphone

Jacks

[mic

(lefteright)]

Dolby

Noise

Reduction

Switch

(Dolby

NR

(2

oute™

in)}

en

ene

enn

&

7—

AC

Power

Voitage

Select

Switch

=

ae

SE

5

|

Play

Button

Record

Button

—

fl

|

(play-

2(>)]

iree-&

(O)]

(cae

“P|

——-

{

eo

4-4

|

i

Stop

Button

Pause

Button

[stop

(m)]

(pause

(11)]

L

Line

Output

Jacks

[LINE

OUT

(LeR)]

——

Line

Input

Jacks

[LINE

IN

(L@R)]

DISASSEMBLY

INSTRUCTIONS

*

The

head

azimuth

can

be

adjusted

by

removing

the

cassette

lid.

|

Fig.

1

Power

supply

(D)

circuit

Flat

Record/

playback

connection

wire

iRecord/playback

=p

‘connection

ss

\

iwire

A

circuit

(F

board

Fig.

5

—2—

RS-M226

Procedure

To

remove

——

.

;

Shown

in

fig.

——

.

1

Case

cover

*

2

screws

1

+

3

screws

(Slide

in

direction

of

arrow)

Bottom

cover

+

Pull

out

the

flat

cable

from

connector

Power

supply

circuit

*

2

Screws

board

*

Cord

clamper

+

Pull

out

the

switch

rod-C

+

2

red

screws

Front

panel

FPR]

WM]

WWWWWw

FL.

meter

unit

+

Meter

cover

and

meter

filter

+

Pull

out

the

FL

meter

unit

+

3

red

screws

*

Pull

out

the

switch

rod-E

+

Pull

out

the

flat

cable

from

connector

[4]

*

Pull

out

the

socket

+

As

shown

in

fig.

3,

push

the

claw

in

the

direction

of

arrow

(®,

{lift

the

main

circuit

board

in

the

direction

of

arrow

@.

+

Remove

the

record/playback

connection

wire

in

the

direction

of

arrow

@)

while

lifting

the

main

circuit

board

in

the

direction

of

arrow

@

as

shown

in

fig.

3.

17

2-4>5->6

Main

circuit

board

+

Cassette

lid

1324-57

Mechanism

unit

*

4

red

screws

»*

Pull

out

the

counter

reset

lever

17

2-45-78

Cassette

holder

Se

gee”

OSA

A

ATPRILOHY:

So

°

«ie

(TPO

|

geelrpatecny

TRB

/TP7\

\

a

A

\

!

IU

J

dein

14°

|

VRS

vR6e

*

ay.

veay:

a

APIN

J

pea

N,

‘

*

ye

swe

~

XN

Tape

speed

adjustment

VR

\

/

TP6

\

K

P

Fig.

1

NOTES:

Keep

good

condition,

set

switches

and

controls

in

the

following

positions,

unless

otherwise

specified

@

Make

sure

heads

are

clean

e

Tape

selector.

Normal

position

@

Make

sure

capstan

and

pressure

roller

are

clean

@

Input

selector:

Line

in

©

Judgeable

room

temperature:

20

+5°C

(68

+

9°F

)

®@

Input

level

controls:

Maximum

®

Dolby

NR

switch:

OUT

RS-M226

ITEM

MEASUREMENT

&

ADJUSTMENT

@

Head

position

(The

head

adjusting

plate

is

provided

to

adjust

the

tape

Screw

(A)

adjustment

touch

of

the

head

in

cue

or

review

mode)

Capstan

Condition

1

Press

the

playback

button

and

pause

button

*

Playback

and

pause

mode

2.

Measure

the

space

between

the

pressure

roiler

and

the

(B)

capstan

Head

Adjusting

Plate

Pressure

Roller

Standard

value:

0.5+0.3mm

Space

(adjustabte)

If

the

measured

value

is

not

within

the

standard

value,

-”

}

untighten

screw

(A),

and

slide

the

head

adjusting

plate

;

in

the

direction

of

arrow

(B)

for

adjustment

Fig.

2

@

Head

azimuth

L-ch/R-ch

output

balance

adjustment

LINE

QUT

adjustment

1.

Make

connections

as

shown

in

fig.

3.

merpeu/

paynael

Condition

+

Playback

mode

:

_

os

sill

:

Playback

the

8kHz

signal

from

the

test

tape

(QZZCFM)

Playback

mode

VIVM

Oscilloscope

Equipment

:

abe

;

i

Ve

2

Oaslotone

ene

(B)

in

fig.

4

for

maximum

output

L-ch

and

Fig.

3

*

Test

tape

(azimuth)

When

the

output

levels

of

L-ch

and

R-ch

are

not

at

c

pees

Mint

~

Q2ZCFM

maximum

at

the

same

time,

readjust

as

follows

Turn

the

screw

shown

in

fig.

4

to

find

angles

A

and

C

(points

where

peak

output

levels

for

left

and

right

channels

are

obtained).

Then,

locate

the

angle

B

between

angles

A

Screw

(B)

Fig.

4

and

C,

i.e.,

a

point

where

L-ch

and

R-ch

output

levels

come

together

at

maximum.

(Refer

to

figs.

4

and

5.)

ee

Roh

peak

level

L-ch/R-ch

phase

adjustment

4

Make

connections

as

shown

in

fig.

6.

5.

Playback

the

8kHz

signal

from

the

test

tape

(QZZCFM)

Adjust

screw

(B)

shown

in

fig.

4

so

that

pointers

of

the

two

VTVMs

swing

to

maximum

and

a

waveform

as

illustrated

in

fig.

7

is

obtained

on

the

oscilloscope

Oscill

VIVM|

illoscope

Playback

{ine

:

mode

Qyt

Vertical

Horizontal

Fig.

6

@

Tape

speed

Tape

speed

accuracy

Record/playback

head

Condition

1

Test

equipment

connection

1s

shown

in

fig.

8.

eae

*

Playback

mode

2.

Playback

test

tape

(QZZCWAT

3,000Hz2)

at

middle

section

eo]

and

supply

playback

signal

to

frequency

counter.

Test

tape

Payback

mode

Digital

electronic

counter

3

Measure

this

frequency

Fig.

8

4.

On

the

basis

of

3.000Hz.

determine

value

by

following

formula

LINE

OUT

Equipment

*

Digital

electronic

counter

or

frequency

counter

*

Test

tape

---

QZZCWAT

t

--

3.000

Tape

speed

accuracy

=

3000

x

100(%)

where.

f

-.

measured

value

f

|

Standard

value:

+1.5%

Adjustment

method

1

Playback

the

test

tape

(middle)

2

Adjust

so

that

frequency

becomes

3.000

Hz

3

Tape

speed

adjustment

VR

shown

in

fig.

1.

Tape

speed

fluctuation

Make

measurements

in

same

manner

as

above

(beginning,

middle

and end

of

tape),

and

determine

the

difference

between

maximum

and

minimum

values

and

calculate

as

follows

:

f:—fe

Tape

speed

fluctuation

=

3

00.

100

(%)

f:

=

maximum

value,

f»

=

minimum

value

Standard

value:

Less

than

1%

Note:

Please

use

non

metal

type

screwdriver

when

you

adjust

tape

speed

accuracy

on

this

unit.

®

Playback

frequency

response

Condition

+

Playback

mode

*

Tape

selector

--

Normal

position

Equipment

*VTVM

+

Test

tape---

*

Oscilloscope

QZZCFM

ony

fig.

3.

Test

equipment

connection

is

shown

in

ITEM

MEASUREMENT

&

ADJUSTMENT

Playback

frequency

response

chart

RS-M226

@

Playback

gain

Condition

*

Playback

mode

*

Tape

selector

-»Normal

position

Equipment

*VTVM

*

Test

tape--:

*

Oscilloscope

QZZCFM

@

Erase

current

Condition

*

Record

mode

*

Tape

selector

--

Metal

position

Equipment

«VTVM

*

Oscilloscope

2.

Place

UNIT

into

playback

mode

aig

100

hee

7

+6d8

3.

Playback

the

frequency

response

test

rade

Se

-

ee

are

$hc8

tape

(QZZCFM)

sae

m@annuiaeal

4

Measure

output

level

at

315Hz,125kHz

|

#8

:

2H

haa

8kHz, 4kHz,

1kHz,

250Hz,

125Hz

and

=

|7

288

ial

248

63Hz.

and

compare

each

output

level

4

erie

q

foe

“To

408

with

the

standard

frequency

315

Hz.

at

eG

oon

|

eas

r

ai

This

*

rivets

LINE

OUT

200Hz

500

Hz

GkHz

10kHz

5.

Make

measurement

for

both

channels

,

6

Make

sure

that

the

measured

value

is

Fig.

9

within

the

range

specified

in

the

frequency

response

chart

(shown

in

fig.

9).

1

Test

equipment

connection

is

shown

in

fig.

3.

2.

Playback

standard

recording

level

portion

on

test

tape

(QZZCFM

315Hz),

and

using

VTVM

measure

the

output

level

at

LINE

OUT

3.

Make

measurement

for

both

channels

Standard

value:

455mV+1dB

[around

280

mV:

at

test

points

TP3

(L-CH)

and

TP4

(R-CH)]

Adjustment

RQ

tf

measured

value

is

not

within

standard,

adjust

VR3

(L-CH),

VR4

(R-CH)

(See

fig.

1

on

page

3).

After

adjustment.

check

“Playback

frequency

response’

again

Test

equipment

connection

1s

shown

in

fig.

10.

Press

the

record

and

pause

buttons

1

2

3.

Set

the

tape

selector

to

metal

position

4

Read

voltage

on

VT

VM

and

calculate

erase

current

by

following

formula

Erase

current

(A)

=

Voltage

across

both

ends

of

R124

1

(Q)

Standard

value:

155+15mA

(Metal

position)

5.

If

measured

value

is

not

within

standard,

adjust

as

follows

Adjustment

1.

Open

the

point

(A)

and

short

the

point

(B)

on

the

main

circuit

board

in

the

wiring

connection

diagram

(See

page

15).

2.

Make

measurement

for

erase

current

3.

Make

sure

that

the

measured

value

is

within

the

erase

current

of

140

mA

to

170mA

4.

If

it

is

beyond

the

value,

carry

out

the

following

adjustments

*

If

the

erase

current

is

less

than

140

mA,

short

the

point

(A)

*

{f

the

erase

current

is

more

than

170

mA,

open

the

points

(A)

and

(B)

©

Overall

frequency

response

Condition

*

Record/playback

mode

*

Tape

selector

--

Normal

position

--CrOQ.

position

--Metal

position

*

Input

level

controls

---

MAX

Equipment

*VTVM

*

AF

oscillator

*

ATT

*

Oscilloscope

*

Resistor

(60002)

*

Test

tape

(reference

blank

tape)

---QZZCRA

for

Normal

“+

QZZCRX

for

CrOz

*-QZZCRZ

for

Metal

Note

:

Before

measuring

and

adjusting,

make

sure

of

the

playback

frequency

response

(For

the

method

of

measurement.

please

refer

to

the

playback

frequency

response}

Overall

frequency

response

adjustment

by

recording

bias

current

Note

1:

On

RS-M226.

overall

frequency

response

1S

adjusted

with

tape

selector

set

at

Normal

Note

2:

Recording

equalizer

is

fixed

1.

Make

connections

as

shown

in

fig.

12.

-

24

dB

signal

through

LINE

IN.

Place

the

set

in

record

2.

Input

a

1

kHz.

mode

Erase

head

Record

mode

=!

vM

Oscilloscope

Fig.

10

Overall

frequency

response

chart

(Norma!)

50Hz

100Hz 200Hz

300

Hz

500Hz

LkHz

2kHz 4kHz

8kKHZ10kHz

Record/playback

!

head

TP]

(L-CH)

TP2

(R-CH)

R1

(t-CH)

R2(R-CH)

Ground

3.

Fine

adjust

the

attenuator

to

obtain

0.4V

LINE

OUT

output.

+

Make

sure

that

the

input

signal

level

is

24+4dB

with

0.45V

output

voltage

Fig.

11

VRQ

(L-CH)

VR10

(R-CH)

LINE

VIVM

——

For

overall

frequency

response

measurement

oscilloscope

VTVM

FVM

oscscoe

arse

ears

bias

current

measurement.

Fig.

12

RS-M226

ITEM

MEASUREMENT

&

ADJUSTMENT

Set

the

tape

selector

to

Normal,

and

load

the

test

tape

(QZZCRA)

Adjust

the

attenuator

to

reduce

the

input

signal

level

by

20dB

Adjust

the

AF

oscillator

to

generate

50Hz,

100

Hz,

200Hz,

500Hz,

1

kHz,

4kHz,

8kHz

and

10

kHz

(ooo

signals,

and

record

these

signals

on

the

test

tape

Playback

the

signals

recorded

in

step

6,

and

check

if

the

frequency

response

curve

is

within

the

limits

shown

in

the

overall

frequency

response

chart

for

normal

tapes

(fig.

11).

(If

the

curve

is

within

the

charted

specifications,

proceed

to

steps

8,

9

and

10.)

If

the

curve

is

not

within

the

charted

specifications,

adjust

as

follows,

Adjustment

(A):

When

the

curve

exceeds

the

overall

frequency

response

chart

specifications

(fig.

11)

as

shown

in

fig

13.

fe

ee

+6dB

+

one

=

t

ct

—4dB

—t—4—f

ett

608

rae

1

—

gap

VkH2

2kHz 4kHz

8kHz1OkHz

Fig.

13

1)

Increase

bias

current

by

turning

VR9

(L-CH)

and

VR10

(R-CH).

(See

fig.

1

on

page

3.)

Repeat

steps

6

and

7

to

confirm

NO

(Proceed

to

steps

8.

9

and

10

if

the

curve

1S

now

within

the

charted

specifications

in

fig.

11.)

3)

If

the

curve

still

exceeds

the

specifications

(tig.

11),

increase

bias

current

further

and

repeat

steps

6

and

7

8.

Switch

the

tape

selector

to

CrO:.

change

test

tape

to

QZZCRX,

and

record

50Hz.

100Hz.

200

Hz,

500Hz,

1

kHz,

4kHz,

8kHz,

10kHz

and

12.5

kHz

signals

the

signals

and

check

if

the

curve

is

within

the

limits

shown

in

the

overall

frequency

response

chart

for

CrO»

tapes

(fig.

15).

9.

Switch

the

tape

selector

to

Metal.

change

test

tape

to

QZZCRZ,

and

Then,

playback

Adjustment

‘B):

When

the

curve

falls

below

the

overall

frequency

response

chart

specifications

(fig

11)

as

shown

in

fig.

14,

4

Ti+

408

re)

ttt

+

208

>

HOB

3

—150B

Toy

~

208

i

=

H

4dB

Pree

teed

+t

tt

eae

roy

|

8

dB

LkH2

2kHz

4kHz

8kHz10kHz

as,

|

oe

i

+4

54B

Fig.

14

1)

Reduce

bias

current

by

turning

VR9

(L-CH)

and

VR10

(R-CH).

2)

Repeat

steps

6

and

7

to

contirm

(Proceed

to

steps

8.

9

and

10

if

the

curve

is

now

within

the

charted

specifications

in

fig

11)

3)

If

the

curve

still

falls

below

the

charted

specifications

(tig.

11),

reduce

bias

current

further

and

repeat

steps

6

and

7

50Hz

100Hz

200Hz

Overall

frequency

response

chart

(CrO2,

Metal)

PTT

1kHz

2kHZ

4kHz

uly

\12.5

KHz

kHz

0

Fig.

15

record

50Hz.

100Hz,

200Hz,

500Hz.

1

kHz,

4kHz,

8kHz,

1OKHz

and

12.5

kHz

signals

playback

the

signals

and

check

if

the

curve

1s

within

the

limits

shown

in

the

overall

frequency

response

chart

for

metal

tapes

(tig.

15).

positions.

*

Read

voltage

on

VTVM

and

caiculate

bias

current

by

following

formula:

Bias

current

(A)

=

Value

read

on

VTVM

(V)

10

(Q)

Then,

10.

Confirm

that

bias

currents

are

approximately

as

follows

when

the

tape

selector

is

set

at

different

around

350A

(Normal

position)

around

450zA

(Cr02

position)

around

700A

(Metal

position)

\

measured

at

TP1

(L-CH)

and

TP2

(R-CH)

@®

Overall

gain

Condition

:

+

Record/playback

mode

*

Tape

selector

seanee

Normal

position

*

Input

level

controls

---

MAX

*

Standard

input

level;

MIC

«+--+

—72+4dB

LINE

IN---

—-24+4dB

Vv

position.

ATT

to

LINE

IN.

A

0.45V.

Using

test

tape,

make

recording.

P

OUT

on

VTVM

becomes

0.45V.

Test

equipment

connection

is

shown

in

fig.

16.

ace

UNIT

into

record

mode,

and

tape

selector

to

normal

Supply

1

kHz

signal

(—24

dB)

from

AF

oscillator,

through

djust

ATT

until

monitor

level

at

LINE

OUT

becomes

layback

recorded

tape,

and

make

sure

the

value

at

LINE

AF

oscillator

LINE

IN

Record/playback

head

Test

tape

Fig.

16

Record

mode

Test

tape

Playback

mode

ytym

Oscilloscope

RS-M226

ITEM

MEASUREMENT

&

ADJUSTMENT

Equipment

:

7.

if

measured

value

is

not

0.45V,

adjust

VR5

(L-CH),

VR6

+*VTVM

_

+

AF

oscillator

(R-CH)

(See

fig.

1

on).

*ATT

*

Oscilloscope

8.

Repeat

from

step

(2)

+

Resistor

(600

2)

»

Test

tape

(reference

blank

tape)

-+-QZZCRA.

for

Normal

@

Fluorescent

meter

.

Test

equipment

connection

is

shown

in

fig.

16.

Condition:

.

As

shown

in

fig.

17,

connect

the

collector

of

Q8

and

peak

reset

terminal.

*

Tape

selector

.

Supply

1kHz

signal

(—24

dB)

to

the

LINE

IN

Normal

position

jack,

then

press

the

record

button.

+

Input

level

controls

--»

MAX

_

Adjust

the

ATT

so

that

the

output

level

at

LINE

OUT

jack

becomes

0.45

V

(The

input

level

at

Equipment:

;

this

condition

is

termed

the

standard

input

Connection

+

VTVM

*

AF

oscillator

level)

uN

cord

*

ATT

.

Adjustment

at

"—20dB"

A.

Adjust

the

ATT

so

that

input

level

is

—20dB

below

standard

recording

level

B.

Adjust

VR7

so

that

the

—20dB

segment

>

lights

up

in

the

—20

+

1dB

range

(L-CH

Ly

ONLY)

(See

fig.

18)

SUTETTTTTTETT

TTT

ET

HTT

5.

Adjustment

at

“OdB":

20

(Fak)

6

©

4+

20+

2

00-68:

A.

Adjust

the

ATT

so

that

the

output

level

at

Fig.

18

LINE

QUT

jack

becomes

0.45V.

MMS

(The

input

level

at

this

condition

is

termed

vesveseeaserisesisaasssersaseesecsese

FOB)

the

standard

input

level.)

t

SHMUOOUUQUAOUUATOL

AUT

A

UAV

ALT

AT

LAUUHT

TUT

.

Adjust

VR8

so

that

the

+1dB

segment

20

(ER)

pee

nae

-2+*0+2

00-628

lights

up

in

the

00.2

dB

range

of

the

Fig.

19

*

Record

mode

Fig.

17

standard

input

level

(See

fig.

19).

CC

Repeat

twice

between

steps

5

and

6

above.

i

.

Adjust

ATT

and

check

that

all

segments

light

SS

ITTULTUUEUUMTUUATUUUTOULCUUUU

TDCI

vt

Pus

vrs

PIVTINERYELULASEAS

EASE

SOEEEEY

ET

up

when

an

input

signal

level

is

increased

to

20

bah

airs

shee

eat

10

dB

higher

than

the

standard

input

level

(See

ee

Fig

20.

sc

a

fig.

20).

©

Dolby

NR

circuit

Dolby

circuit

frequency

response

check

Condition:

@

Check

of

the

Dolby-B

type

encoder

characteristics

*

Record

mode

.

Make

connections

as

shown

in

fig.

21.

*

Dolby

NR

switch

-+-

IN/OUT

.

Set

the

unit

to

the

record

mode.

(NR

select

switch

is

OUT.)

*

Dolby

NR

select

switch

.

Apply

a

1

kHz

signal

to

LINE

IN.

++B/C

.

Adjust

the

ATT

so

that

the

output

level

at

TP3

(L-CH)

and

TP4

(R-CH)

is

12.3

mV.

*

Input

level

controls

MAX

.

The

output

level

at

14

should

be

0dB.

Equipment:

.

Set

the

NR

select

switch

to

B,

and

make

sure

that

the

output

signal

level

at

14

of

IC3

(L-CH)

and

*VTVM

—

*

AF

oscillator

IC4

(R-CH)

is

+6dB+2.5dB.

*

ATT

*

Oscilloscope

.

Set

the

NR

select

switch

to

OUT,

and

adjust

the

frequency

to

5kHz.

The

output

signal

level

at

*

Resistor

(600

Q)

14

should

be

OdB.

;

.

Set

the

NR

select

switch

to

B

and

make

sure

that

the

output

signal

level

at

14

of

IC3

TP3

(L-CH)

and

IC4

(R-CH)

is

8dB+2.5¢B.

re

©

Check

of

Dolby-C

type

encoder

characteristics

9.

Repeat

steps

1-5

above.

10.

Set

the

NR

select

switch

to

C

and

make

sure

that

the

output

signal

level

at

14

of

IC3

;

(L-CH)

and

IC4

(R-CH)

is

11.5dB+2.5dB.

fate

{ite

(L-CH)

2

11.

Set

the

NR

select

switch

to

OUT

and

adjust

Ica

(R-CH)

EN

ere

the

frequency

to

5kHz.

The

output

signal

at

Fig.

21

14

should

be

OdB.

9-

.

Set

the

NR

select

switch

to

C

and

make

sure

that

the

output

signal

level

at

14

of

IC3

(L-CH)

and

IC4

(R-CH)

is

8.5dB+2.5dB.

RS-M226

ELECTRICAL

PARTS

LOCATION

Q14,

15

5-Core

flat

cable

White

line

aa

=

Connector

[4]

ree

(Flat

Cable

connecter)

Open

the

lid

of

connector

G]

in

the

direction

of

the

arrow

as

shown

above,

and

extract

the

5-Core

flat

cable

to

disconnect.

REPLACEMENT

PARTS

LIST

Important

safety

notice

Components

identified

by

A

mark

have

special

characteristics

important

for

safety.

When

replacing

any

of

these

components,

use

only

manufacturer’s

specified

parts.

Ref

No.

Part

No.

|

Part

Name

&

Description

Ref No.

Part

No.

Part

Name

&

Description

ELECTRICAL

PARTS

E7

QuS1961S

Flat

Cable

Connector

E8

QJUT1090

Terminal-A

E1

QWY4122Z

Record/Playback

Head

(Test

Point)

E2

QWY2138Z

Erase

Head

EQ

SJT777

Terminal-B

E3

(AC

Power

Cord)

[D]

A

RJA23ZC

AC

Power

Cord

E10

NO39

Heat

Sink

[For

all

European

areas

except

United

Kingdom.}

([B)A

QFC1205M

AC

Power

Cord

E11

QJS1923TN

9

Socket

{For

United

Kingdom.]

E12

QJT1054

Contact

4

QSiFLOO6F

FL

Meter

E13

QJS1921TN

3

Socket

5

QJP1921TN

3

Post

E14

A

QTF1054

Fuse

Holder

6

QJP1923TN

9

Post

BLOCK

DIAGRAM

Recording

System(L-CH

ONLY)

RS-M226

INPUT

SELECT

SWITCH

=_>—

>

~

LINE

<—»®

MIC

$2-4

$2.2

LEVEL

CONTROL

a

oT>

|

©

pr

sts]

Ly

Pp

VR5

RECORDING

FOAM

GAIN

ADJUSTMENT

VR

MICROPHONE

AMP

RECORD/PLAY

BACK

HEAD

=

§

VR10

BIAS

Y-

CURRENT

@)

)

ADJUSTMENT

VR

Metal

>

e

(6)

J

x

$6-3

Cro,

[-—}

O ©

TAPE

SELECT

is

Se

oe

Ee

5

0

fo

SWITCH

Normal

07

RECORD

INDICATOR

a

ERASE

HEAD

|

Metal

-O

6-1

cro,

O

|

!

|

Le

BIAS

OSC

Playback

System

(L-CH

ONLY)

RECORD/PLAYBACK

HEAD

1C1

PLAYBACK

EQ

AMP

PLAYBACK

GAIN

ADJUSTMENT

a

MUTING

FF/REWIND

CONTROL

|

MUTE

i

r

FF/REWIND

CR

NETWORK

MUTING SWITCH

(70ys)

|

L

Cro,

Normal

©

O

Metal

O

S6-2

i

TAPE

SELECT

SWITCH

Power

Supply

System

1C7

a

METER

&

HEADPHONES

AMP

Th

VOLTAGE

REGULATOR

DOLBY

NR

SECTION

103-6

FL

METER

SECTION

IC8

Q15

VOLTAGE

REGULATOR

NOTE:

*

Dolby

NR......

OFF

°

(mmm

)

this

arrow

indicates

the

flow

of

the

recording

signal.

¢

(<>)

)

this

arrow

indicates

the

flow

of

the

playback

signal.

MUTING

CONTROL

Q11—13

FL

METER

FILAMENT

(\

D13—16

|

RECTIFIER

CAPSTAN

MOTOR

T

HEADPHONES

(2)

~~

V

METER

&

HEADPHONES

RS-M226

DOLBY

SYSTEM

(L-CH

ONLY)

LINE

OUT

Dolby-B

Encode

MIC.

MIC

IN

AME

Ic3

section

to

check

the

frequency

Mien

tiie

iit

NE6S4N

response

of

the

Dolby

circuit

in

the

O

HEADPHONES

AMP

A +

vRi

Ics

illustration.

NE652N

LINE

IN

5

()

q

O

oO

C

RECORD

AMP

MPX

FILTER

(2)

HEADPHONES

JACK

METER

HEADPHONES

LINE

OUT

Q8,

9

PEAK

HOLD

O

SET/RESET

UI

+4

H.F—O—O—0O

>

IS

YMd

A0/0/8

O—D—_5—O—©

3

HIGH

PASS

FILTER

im

N

Dr

[2

ae

O)—©)

S)—®)

(©)

Le

>

©

DOLBY

NR

CIRCUIT

FREQUENCY

RESPONSE

HEADPHONES

Pee

1kHz:

+6dB+2.5dB

JACK

Ty

5kHz:

+

8dB+2.5dB

Dolby-B

Decode

VR5

Q8,

9

PEAKHOLD

SET/RESET

METER

HEADPHONES

LINE

OUT

ddNS

YMd

AsO/0/8

x

POWER

ON/OFF

SWITCH

~~

&£

HIGH

PASS

FILTER

PB

EQ

AMP

Refer

to

Item

©

“Dolby

NR

circuit”

of

the

measurement

and

adjustment

Dolby-C

Enca

LINE

IN

(G

O

E

MPX|

METER

HEADPHONES.

LINE

OUT

(G

Spectra

skewing

networ!

LS

Low

level

stage

integrating

filter

Anti-satur:

Low

level

stage

high

pass

filter

REC

EQ

AMP

Dolby-C

Deca

METER

HEADPHONES

LINE

OUT

Spectral

skewing

network

Low

level

stage

integrating

filter

PB

EQ

Low

level

stage

high

pass

filter

Anti-Saturation

filta

RS-M226

LINE

OUT

METER

&

HEADPHONES

AMP

HEADPHONES

JACK

~~

Q8,

9

PEAK

HOLD

SET/RESET

FL

METER

DRIVE

FL

METER

YN)

—~___

$4

an

|

!

|

Ste)

LINE

OUT

©

&

HEADPHONES

AMP

JACK

—vV,

Q8,

9

PEAKHOLD

SET/RESET

POWER

ONIOFF

~1.

SWITCH

C200

RS-M226

DOLBY

SYSTEM

(L-CH

ONLY)

Dolby-B

Encode

Refer

to

Item

©

“Dolby

NR

circuit”

of

the

measurement

and

adjustment

AMP

section

to

check

the

frequency

MIC

IN

Ic3

babahietes

NE654N

response

of

the

Dolby

circuit

in

the

vRi

Ics

illustration.

NE652N

LINE

IN

(1)

q

O

e

RECORD

g

;

MPX

FILTER

a

i

NeTER

SS

es

l

@

HEADPHONES

(4)

+

>

<2)

LINE

OUT

ar<d

G)

N

ee

cE

all

@

Yl

BUFFER

AMP

<6

|

i

(4)

3

G)

(6)

HIGH

PASS

FILTER

DOLBY

NR

CIRCUIT

FREQUENCY

RESPONSE

Sy

ddNS

YMd

©

Low

level

stage

integrating

filter

Low

level

stage

high

pass

filter

TT)

i

>=

o—o—o-4

1kHz:

+6dB+2.5dB

VR5

REC

EQ

AMP

5kHz:

+

8dB+2.5dB

=

Dolby-B

Decode

IC3

1c5

NE654N

NE652N

METER

HEADPHONES

LINE

OUT

IddNS

YMd

Z|

~~

&

HIGH

PASS

FILTER

Low

level

stage

integrating

filter

PB

EQ

AMP

Low

level

stage

high

pass

filter

rd

Refer

to

Item

©

“Dolby

NR

circuit”

of

the

measurement

and

adjustment

section

to

check

the

frequency

response

of

the

Dolby

circuit

in

the

illustration.

Dolby-C

Encode

MIC

IN

MIC

AMP.

IC3

NE654N

VR1

1c5

</

£

LINE

IN

0

NE652N

HIGH

LEVEL

STAGE

:

-

MPX

FILTER

High

level

stage

ae

high

pass

filter

METER

HEADPHONES

High

level

stage

integrating

filter

LINE

OUT

High

level

stage

main

chan

signal

C—O

0

“Kr

I<]

©)

o—é

@)

High

level

stage

side

chain

net

work

Spectral

skewing

network

Low

level

stage

side

chain

net

work

Low

level

stage

Low

level

stage

main

chain

signal

integrating

filter

Anti-saturation

filter

os

Bs

oe

ie

=

a

=o)

ile

)——-©)-—®

Low

level

stage

i

high

pass

filter

Ma

ta

pe

ig

we

ee

le

4

LOW

LEVEL

stage”

DOLBY

NR

CIRCUIT

FREQUENCY

RESPONSE

kHz:

+11.5dB+2.5dB

$

#

—

Dolby-C

Decode

Ic3 1c5

HIGH

LEVEL

NE654N

NE652N

STAGE

High

level

stage

signal

High

level

stage

high

pass

filter

METER

High

level

stage

’

integrating

filer

HEADPHONE:

LINE

OUT

High

level

stage

main

chain

signal

TddNS

YMd

XK

4sd0/0/8

High

level

stage

side

chain

network

Spectral

skewing

network

Low

level

stage

side

chain

network

Low

level

stage

integrating

filter

Low

level

stage

high

pass

filter

Anti-Saturation

filter

LOW

LEVEL

STAGE

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